1. Field of the Invention
This invention relates to server protection and more particularly relates to maintaining communication with a server, such as an advanced management module (“AMM”), or standby server (standby AMM) during a broadcast storm or denial-of-service (“DoS”) attack.
2. Description of the Related Art
While publicly accessible, open networks such as the Internet provide increased flexibility and accessibility, open networks also expose the networks to cyber attacks such as web vandalism, propaganda, unwanted email, gathering of private data, denial-of-service (“DoS”) attacks, equipment disruption, and even attacks on critical infrastructure. Mass marketers, pranksters, counterculturalists, activists, terrorists, and even hostile governments engage in such activities for various reasons to disrupt the flow of communication, intentionally or as a byproduct of their activities.
Denial-of-service attacks are typically an intentional form of a cyber attack intended to prevent access to a computer system, server, or other computer resource by flooding the system or server with unwanted data at a high rate. Systems and servers under a DoS attack, because of the sheer volume of incoming data, typically cannot cope with the increased network traffic without either slowing responses to data requests to a near stop or stopping service of data requests all together.
Cyber attacks directed at a specific Internet Protocol (“IP”) address or may disrupt a device by flooding the network from which the device communicates with unwanted data through a broadcast. The latter stages of this second type of attack are sometimes called a broadcast storm and the accumulation of broadcast and multicast traffic on a computer network is sometimes called broadcast radiation. The first type of cyber attack on a particular IP address is herein referred to as a DoS attack and flooding of a computer network with broadcast or multicast traffic is herein referred to as a broadcast storm.
Prior art methods of dealing with a DoS attack or broadcast storm typically rely on shutting down a server or device under attack. This method has several drawbacks. First, when a server or device is shut down, reboot may be lengthy and may delay server access until long after an attack is over. In another scenario, upon reboot the server or device might find that it is still under attack. A primary server with a standby server available may find itself under DoS attack or broadcast storm and may switch to the standby server only to find that the standby server is also under attack.